Diamond is a valuable material due its properties of hardness (10 on the Mohs hardness scale), heat stability, high room temperature thermal conductivity (about 2000 W/mK), very low rms vibration at room temperature (0.002 nm), a high index of refraction (2.4), optical transparency from infrared through visible, and UV fluorescence. Because of its high band gap (5.45 ev) it is a superb electrical insulator (10.sup.16 ohm). Boron doped (blue) diamond has been found to be p-type semiconductor having a high hole mobility and electrical breakdown strength. Such properties may afford diamond utility with respect to substrates for micro-electronic devices, ultraviolet light protective coatings, high energy laser device windows, and even diamond semiconductor devices. Such applications require that diamond be ultra-pure.
Many synthetic methods for diamond are known. These methods produce diamond either from elemental carbon or from elemental carbon obtained from a compound or compounds of carbon which methods subject elemental carbon to conditions under which the carbon will form the crystalline species known as diamond. Typically, these methods involve high pressure, high temperatures, or high energy discharges. Moreover, post treatments are frequently necessary for purification. Most of these methods do not produce ultra-pure diamond, however.